Johnston's Army of Tennessee has settled into the Kennesaw line, consisting principally of the twin elevations of Big Kennesaw Mountain and Little Kennesaw Mountain, and the pursuing Federal forces under Sherman had begun to probe this new line in search of weak spots on June 19
After judging the Kennesaw line to be too strong to take by regular assault—even though he will attempt to do just that five days later—Sherman decides to fix Johnston's line in place with his left wing, the Army of the Tennessee, under McPherson, while maneuvering his center and left wing, the Army of the Cumberland, under Thomas, into position to turn Johnston's left flank somewhere south of the Powder Springs Road.
In obedience to Sherman's orders, Thomas moves the XX Corps, under Major General Joseph Hooker, into the area; Hooker will be supported in this operation by the single-corps Army of the Ohio, under Schofield, who will guard Hooker's far right.
Johnston correctly anticipates Sherman's movements, and decides to counter them by moving one of his three corps, under Hood, from its reserve position near Marietta south and west along Powder Springs Road to the vicinity of Mount Zion Church; this will both extend his left and counter Sherman's turning movement.
Hood, ordered to pull out of line on June 20, had begun the movement on the morning of June 21.
His corps passes through Marietta and is in place by June 22.
Hood's corps attempts an unsuccessful attack at Peter Kolb's farm (the Battle of Kolb's Farm) south of Little Kennesaw Mountain.
Major Genera William W. Loring succeeds to command Polk's corps.
The battle has demonstrated Hood's main deficiency as a battlefield commander: his willingness to attack without adequate reconnaissance.
He will go on to make the same error, this time as an army commander, at three future engagements in the Atlanta Campaign—the Battle of Peachtree Creek, the Battle of Atlanta, and the Battle of Ezra Church—with exceedingly costly results.
On the Federal side, the victory is marred by growing friction between Sherman and Hooker.
